WO2017182574A1

WO2017182574A1 - Crude oil composition comprising an additive for improving the flow properties of paraffin-containing crude oil

Info

Publication number: WO2017182574A1
Application number: PCT/EP2017/059408
Authority: WO
Inventors: Artem UCHAEV; Alisa GAPCHENKO; Hans-Ulrich Moritz; Werner Pauer
Original assignee: Universität Hamburg
Priority date: 2016-04-21
Filing date: 2017-04-20
Publication date: 2017-10-26
Also published as: RU2018135050A; US20190062660A1; RU2740208C2; RU2018135050A3; EP3445837A1

Abstract

The invention relates to the improvement of the flow properties of paraffin-containing crude oil. The problem addressed by the present invention is that of providing a means of favourably influencing the pour point of crude oil and hence improving the flow properties of paraffin-containing crude oil. In one aspect, the invention, for this purpose, provides a crude oil composition comprising a paraffin-containing crude oil and an amount of an additive that brings about lowering of the pour point of the crude oil, wherein the additive comprises at least one copolymer composed of at least two comonomers, and wherein all comonomers that make up the copolymer are selected from the groups (a) and (b) of comonomers, and wherein group (a) consists of comonomers formed from acrylic acid and methacrylic acid, and group (b) consists of comonomers formed from styrene and a styrene derivative.

Description

CRUDE OIL COMPOSITION, COMPREHENSIVE ADDITIVE FOR IMPROVING THE FLUID CHARACTERISTICS OF PARAFFIN-CONTAINING CRUDE OIL

The invention relates to a crude oil composition comprising an additive for improving the flow properties of paraffinic crude oil, a process for producing a crude oil composition having a reduced pour point compared to the crude oil, and the use of an additive for improving the flow properties of paraffinic crude oil. Crude oil is a mixture of substances consisting mainly of hydrocarbons. In addition, crude oil contains oxygen and sulfur containing compounds such as naphthenic acids, phenol, aldehydes, thioesters and various heterocyclic compounds. A majority of the hydrocarbons is a mixture of straight-chain unbranched paraffins having 1 to 30 carbon atoms, wherein gaseous and solid hydrocarbons are dissolved in the liquid hydrocarbons.

At low temperatures, the paraffins in the crude oil cause particular problems in terms of flow properties. With pure crude oil, paraffins begin to crystallize out and agglomerate at temperatures around 40 to 50 ° C, which significantly worsens the flow properties of the crude oil. The temperature at which crude oil loses its flowing properties is referred to as pour point, which leads to deposits on the inner walls of the pipes during transport of the crude oil through pipelines, especially in winter, in some cases even to complete blockage (eg in case of a temporary stoppage of crude oil in a pipeline).

To restore flow, there are mechanical, physical and chemical methods such as the following:

1) scraping the crystallized paraffins from the pipe inner wall by using a

Pig.

2) heating the crude oil to a temperature higher than that

Crystallization temperature of paraffins.

3) Use of different solvents to dissolve heavy paraffins. In recent years, chemical additives (so-called paraffin inhibitors) have been developed. Such additives are macromolecular substances which by physical interaction with paraffins modify their size, shape and adsorption properties. This leads to the formation of smaller paraffin crystals, which no longer aggregate and the

No longer impair the flow properties of crude oil. Paraffin inhibitors are predominantly paraffin-like in structure and generally have polar groups in the side chains. Among other things, these branches have the task of countering the crystal formation of the paraffins. The additives lead to a lowering of the pour point of crude oil.

As paraffin inhibitors, polymers, copolymers and terpolymers having an average molecular weight of 3,000 to 100,000 g / mol are known. The effectiveness of the additives depends on their chemical composition and their concentration.

US 3 735 770 discloses a process for improving the flow properties of crude oils. This process involves the addition of copolymers of ethylene with unsaturated ones

Carboxylic acid esters or of alkylphenols to the oil. US 3,393,057 discloses a terpolymer as a pour point depressant consisting of 10 to 90% by weight of C10-C24a olefins, 2.5 to 35% by weight of butadiene and 2.5 to 35 Wt% styrene or indene and has a kinematic viscosity of 35 to 600 centistokes at 210 ° F. US 3,951,929 discloses a pour point improver comprising an interpolymeric acrylic ester having an average molecular weight of 3,000 to 100,000.

EP 1 086 964 B2 discloses a pour point improver of (meth) acrylic acid copolymer. The poly (meth) acrylic acid ester copolymer consists of 5 to 60 wt .-% (meth) acrylic acid esters of alcohols having 11 to 15 carbon atoms, and 95 to 40 wt .-% of (meth) acrylic acid esters of

Alcohols with 16 to 30 carbon atoms. DE 2048308 Al discloses as a paraffin inhibitor a mixture of ethylene-vinyl ester copolymer having a molecular weight of 3,000 and 9,000. From 0.01% to 0.5% by weight of the mixture is added to the crude to reduce the pour point. EA 012243 Bl discloses a pour point improver consisting of a product

Polyoxyethylensorbitanester condensation with carboxylic acid anhydrides. The additive improves the depressive properties, flow and viscosity of petroleum and petroleum products. The optimum result is achieved with addition of 50 to 5,000 ppm. WO 2001/096503 A2 discloses an additive for improving the flowability of mineral oil. This contains: a) Copolymers of 80 to 96.5 mol% of ethylene and 3.5 to 20 mol%

Vinyl esters of carboxylic acids having 1 to 20 carbon atoms and / or (meth) acrylic acid esters of alcohols having 1 to 8 carbon atoms, and homopolymers or copolymers of C 10 -C 30 -alkyl-bearing esters of ethylenically unsaturated carboxylic acids with up to 20 mol% olefinic unsaturated compounds, b) a poly-α-olefin having a molecular weight of 250 to

5,000 derived from monoolefms of 3 to 5 carbon atoms; and c) an organic acid selected from certain alkylphenol-aldehyde resins and aliphatic and / or aromatic sulfonic acids. No. 7,790,821 B2 discloses a process for producing a stable latex dispersion consisting of (co) polymers with one or more (meth) acrylic acid ester monomers of alcohols having from 6 to 40 carbon atoms, optionally with one or more monomers, of non-water-soluble (meth) acrylic and / or vinyl type, and optionally one or more polar monomers selected from (meth) acrylamides and their derivatives, and optionally one or more monomers selected from the ethylenically unsaturated mono- and / or dicarboxylic acids or their anhydrides are selected. The latex dispersion inhibits the separation of paraffins in the crude oil.

EP 0 120 512 A2 discloses a pour point improver comprising a minor amount of a polymer having predominantly aliphatic hydrocarbon side chains of at least 14 carbon atoms, the polymer having a branched carbon backbone. EP 0 332 000 A2 discloses the use of copolymers of acrylic and / or methacrylic acid esters of higher alcohols or alcohol cuts having at least 16 carbon atoms in the alcohol radical and not more than 5 wt .-% maleic anhydride as flow improvers in paraffin-rich crude oils and / or petroleum fractions with Eigenfließpunkten above 25 ° C to lower their pour points to values below 15 ° C.

US 4,284,414 discloses mixed alkyl esters as flow improvers for crude oil prepared by reacting a mixture of two or more specific ones

monohydric alcohols with interpolymers derived from (i) α, β-unsaturated dicarboxylic acids or derivatives thereof, and (ii) vinyl aromatic monomers having up to 12 carbon atoms.

There is still a need to improve the flow properties of crude oil. Object of the present invention is therefore to provide a way to favorably influence the pour point of crude oil and thus to improve the flow properties of crude oil.

In a first aspect, the invention provides a crude oil composition comprising a paraffin-containing crude oil and an amount of an additive which causes a lowering of the pour point of the crude oil, the additive comprising at least one copolymer composed of at least two comonomers, all of which being the copolymer comonomers are selected from the groups (a) and (b) of comonomers, and wherein the group (a) consists of comonomers of acrylic acid and methacrylic acid, and the group (b) consists of comonomers of styrene and a styrene derivative.

It has surprisingly been found that the use of a copolymer of at least two comonomers, wherein the comonomers are selected from groups (a) consisting of acrylic acid and methacrylic acid, and (b) consisting of styrene and a styrene derivative, improve the cold properties of crude oil can. Examples of corresponding copolymers are acrylic acid / styrene, methacrylic acid / styrene or (meth) acrylic acid / styrene derivative, or else Mixed polymers of a mixture of acrylic acid and methacrylic acid and styrene or styrene derivative.

By a "paraffine-containing crude oil" is meant a crude oil (crude petroleum) containing hydrocarbons in the form of paraffins. "Paraffins" as used herein are acyclic, saturated, straight-chain or branched hydrocarbons (alkanes) having 1 to 33

Carbon atoms, in particular having 12 to 33 carbon atoms or 16 to 20

Understood carbon atoms. A "paraffin-containing crude oil" is used here in particular when the paraffin content is at least 10%.

The term "acrylic acid" (propenoic acid, CAS number 79-10-7) is understood as meaning a compound of the formula CH ₂ = CH-COOH.

The term "methacrylic acid" (2-methylpropenoic acid, CAS number 79-41-4) is understood as meaning a compound of the formula CH ₂ = C (CH 3) -COOH.

The term "styrene" (phenylethene, CAS number 100-42-5) is understood as meaning a compound of the following formula:

The term "styrene derivative" is understood here to mean a compound according to the following formula:

wherein R ² , R ³ , R ⁴ , R ⁵ and R ^{6 are} each independently H, or alkyl, preferably H, methyl, or C 2 -C 12 alkyl, with the proviso that not all R ² to R ^{6 are} H are. An example of a styrene derivative is 4-methylstyrene (R ⁴ = CH ₃ ; R ² , R ³ , R ⁵ and R ⁶ = H). A compound in which all R ² to R ^{6 are} H would correspond to styrene.

The formulation according to which the comonomers of the at least one copolymer are selected from groups (a) and (b) of comonomers wherein group (a) consists of comonomers of acrylic acid and methacrylic acid and group (b) of comonomers of styrene and a styrene derivative "or the formulation according to which the at least one

Copolymer "composed of at least two comonomers, all of which

Copolymer composing comonomers are selected from the groups (a) and (b) of comonomers, wherein the group (a) of comonomers of acrylic acid and

Methacrylic acid, and the group (b) of comonomers of styrene and a

Styrene derivative "means that the copolymer is in any case composed of at least one type of comonomer from group (a) and at least one type of comonomer from group (b). Examples of copolymers would therefore be those of two comonomers, for example the comonomers acrylic acid (cf. Group a) and styrene (group b), acrylic acid (group a) and styrene derivative group b), methacrylic acid (group a) and styrene (group b) or methacrylic acid (group a) and styrene derivative (group b), but these also include copolymers from more than two comonomers, for example those of acrylic acid, methacrylic acid (group a) and styrene (group b), acrylic acid, methacrylic acid (group a), styrene and styrene derivative (group b), acrylic acid (group a), styrene and styrene derivative (group b), or methacrylic acid (group a), styrene and styrene derivative (group b) In principle, mixed polymers of more than four comonomers are also suitable, for example a copolymer of acrylic acid and methacrylic acid (Group a), styrene, styrene derivative 1 and styrene derivative 2 (Group b). Preference is given to copolymers of acrylic acid and styrene or methacrylic acid and styrene.

The formulation according to which "the additive comprises at least one copolymer of at least two comonomers" or "the additive comprises at least one copolymer composed of at least two comonomers" includes, besides additives, a copolymer having a substantially uniform comonomer composition, i. a copolymer of two particular comonomers (e.g., acrylic acid and styrene), also mixtures of copolymers of different comonomer composition, as long as the copolymers of the copolymer blend have the composition specified above, i. are composed of at least two comonomers selected from comonomers of groups a and b. The copolymer mixture may contain, for example, copolymers of acrylic acid and styrene, methacrylic acid and styrene and / or acrylic acid, methacrylic acid and styrene.

The term "improving the flow properties of paraffinic crude oil" is understood here to mean a reduction in the pour point of the crude oil, the pour point being the temperature at which crude oil loses its flowing properties. The pour point can be determined, for example, according to ASTM D5853. A that

Crude oil composition containing additive according to the invention thus has a lower pour point compared to crude oil. For example, a crude oil may have a pour point of 12 ° C while the crude oil composition has a pour point of -5 ° C.

The term "pour point improver", "pour point depressant" or "paraffin inhibitor" is understood here to be an additive which lowers the pour point of a crude oil, preferably by at least 1 ° C., more preferably by at least 2 ° C., by at least 3 ° C., by at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C. The term "alkyl" includes saturated and unsaturated aliphatic (non-aromatic)

Groups, including straight-chain alkyl groups (eg methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl) and branched-chain alkyl groups (eg isopropyl, tert-butyl, Isobutyl). The term "C ₂ -C ₂ alkyl" means an alkyl group having 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 or 12 carbon atoms.

If a molecular weight is stated here in relation to a copolymer used according to the invention, this means the weight-average molecular weight (unit g / mol).

Range indications such as "10,000 to 30,000" are always to be understood here so that everyone

Intermediate value is disclosed with. An arbitrary smaller area of the area should also be disclosed, wherein the smaller area also includes areas which do not include any of the limit values of the area. For example, an indication such as "10,000 to 30,000" includes not only areas such as "10,000 to 29,000" or "15,000 to 30,000" but also ranges of "15,000 to 28,000" or "20,000 to 29,000" or "12,000 to 27,000" individual values within the range are expressly included, and not just its limits.

A copolymer used according to the invention has the general structure according to the following formula I:

wherein R ¹ is H or methyl, R ^2, R ^3, R ^4, R ⁵ and R ^6, each independently, H or alkyl, preferably H, methyl, or C ₂ -C ₂ are alkyl, and m is the number of the comonomer (s) of group (a) (acrylic acid, methacrylic acid) and n indicates the number of comonomers or comonomers of group (b) (styrene, styrene derivative) in the copolymer. The above formula indicates schematically only a general structure and is in particular not to be understood that this must be an alternating copolymer or block copolymer. Rather, it may also be a random copolymer. As already indicated, the formula is also not to be understood that only two comonomers, eg

Acrylic acid and styrene in which copolymer is present. Rather, mixtures of more than two comonomers are suitable (for example acrylic acid, methacrylic acid and styrene), but with the proviso that always at least one comonomer from group a and at least one comonomer from group b is present.

The preparation of copolymers is basically known (see, for example, Ullmanns Enzyklopadie der Technischen Chemie, Vol. 21, pages 305 to 403). In this case, monomers are dissolved in an organic solvent and polymerized in the presence of a radical initiator at temperatures in the range of, for example, 30 to 150 ° C.

In a preferred embodiment of the crude oil composition according to the invention, the additive comprises 0.05 to 50% by weight, preferably 0.5 to 50% by weight, 1 to 50% by weight, 2.5 to 50% by weight or 5 up to 50% by weight, more preferably 5 to 45% by weight, 10 to 45% by weight, 15 to 45% by weight or 15 to 40% by weight, particularly preferably 20 to 40% by weight of the at least one copolymer.

The at least one copolymer used in the additive is in a preferred

Embodiment composed of two comonomers, wherein the comonomer from group (a) of comonomers is acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from group (b) of comonomers is styrene or a styrene derivative, preferably styrene.

The molecular weight or molecular weight distributions (MWD) of the copolymers used according to the invention in the crude oil composition can be in a range from 2,000 to

500,000 g / mol, preferably from 5,000 to 300,000 g / mol. The molecular weight distribution can be determined, for example, by means of gel permeation chromatography against polystyrene standards. The conversion of acrylic acid, for example, after the reaction by

Reverse phase high performance liquid chromatography (RP-HPLC). For example, H2O / K2HPO4 (pH = -2.7) can be used as the buffer and acetonitrile as the eluent. The conversions of styrene can be determined, for example, after the reaction by means of gas chromatography (GC). The average molecular weight or molecular weight distribution of the copolymer or copolymer mixture in the additive is preferably that used to prepare the

Crude oil of the invention used crude oil, in particular the

Molar mass distribution of the paraffins contained therein, adjusted. In a preferred

Embodiment of the crude oil composition according to the invention, the at least one copolymer has an average molecular weight of 2,000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to 30,000 g / mol, 10,000 to <30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol.

In a further preferred embodiment of the invention

Crude oil composition is in the additive, the proportion of the comonomer (a) to the at least one copolymer, based on the comonomer mixture, 0.6 to <10.0 wt .-%, preferably 1.0 to <10.0 wt .-%, more preferably 1.0 to 9.0% by weight, 2.0 to 9.0% by weight, 3.0 to 9.0% by weight, 4.0 to 9.0% by weight, 5.0 to 9.0 wt% or 5.0 to 8.0 wt%.

In a particularly preferred embodiment of the invention

Crude oil composition in the additive, the at least one copolymer has an average molecular weight of 10,000 to 30,000 g / mol, and a proportion of acrylic acid of 1.0 to

<10.0 wt%, preferably from 2.0 to 9.0 wt%, more preferably from 3.0 to 9.0 wt%, 4.0 to 9.0 wt%, 5.0 to 9.0 Wt .-% or 5.0 to 8.0 wt .-%, for example, 5 wt .-%, on.

The additive preferably also comprises at least one organic solvent in addition to the at least one copolymer, wherein the organic solvent is preferably an aromatic solvent, and is more preferably selected from aromatic

Hydrocarbons such as toluene, xylene, trimethylbenzene, ethylbenzene, dimethylnaphthalene or a mixture thereof. The organic solvent is preferably chosen so that it is readily soluble in crude oil and at the same time the copolymer or

Copolymer mixture dissolves well. The additive may be composed of the at least one copolymer and the at least one organic solvent. The share of

Solvent on the additive may in this case, depending on the proportion of at least one Copolymer, for example 50 to 99.95% by weight, 50 to 99.5% by weight, 50 to 97.5% by weight, 50 to 95% by weight, 55 to 95% by weight. %, 55 to 90 wt .-%, 55 to 85 wt .-%, 60 to 85 wt .-% or 60 to 80 wt .-% amount. For example, the additive may be composed of 20% by weight of the at least one copolymer and 80% by weight of the at least one solvent.

For the preparation of a copolymer, as radical initiators (initiators) e.g. Azo-bis-isobutyronitrile, esters of peroxycarboxylic acid such as t-butyl perprivalate and t-butyl-per-2-ethylxeanoate or dibenzoyl peroxide or other peroxides and azo compounds can be used. At higher temperatures (for example, above 80 ° C) and the thermal initiation of the polymerization can be triggered by reactions of the styrene. The initiators can be added to the comonomer mixture, for example, in an amount of 0.05 to 10 wt .-%. The desired properties of the copolymer can be determined, for example, by varying the reaction parameters pressure and temperature and by the ratio of initiator to

Monomer (s) can be adjusted.

A preferred crude oil composition of the invention comprises an amount of the additive containing a pour point depression of the crude oil of at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C causes.

In a further preferred embodiment, the inventive

Crude oil composition, for example, 1 to 1000 ppmw, preferably 5 to 1000 ppmw or 5 to 750 ppmw, particularly preferably 5 to 500 ppmw, 10 to 500 ppmw, 10 to 300 ppmw or 15 to 250 ppmw of the at least one copolymer.

In another aspect, the present invention also relates to a process for preparing a crude oil composition having a pour point lowered from the crude oil, comprising adding an additive to the crude oil in an amount effective to lower the pour point, the additive comprising at least one copolymer, which is composed of at least two comonomers, all of which is the copolymer

comonomers are selected from groups (a) and (b) of Comonomers, and wherein the group consists of (a) of comonomers of acrylic acid and methacrylic acid, and the group (b) of comonomers of styrene and a

Styrene derivative exists. Preferably, an additive is added to the crude oil, which is 0.05 to 50 wt .-%, preferably 0.5 to 50 wt .-%, 1 to 50 wt .-%, 2.5 to 50 wt .-% or 5 bis 50 wt .-%, more preferably 5 to 45 wt .-%, 10 to 45 wt .-%, 15 to 45 wt .-% or 15 to 40 wt .-%, particularly preferably 20 to 40 wt .-% of comprises at least one copolymer. In a preferred embodiment of the method according to the invention, an additive is added to the crude oil,

a. wherein the at least one copolymer has a weight average molecular weight of 2,000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to <30,000 g / mol, 10,000 to 30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol or 10,000 to 25,000 g / mol, and / or

b. wherein the proportion of the comonomers of group (a) to the at least one copolymer, based on the comonomer mixture, 0.6 to <10.0 wt .-%, preferably 1.0 to <10.0% by weight, further preferably 1.0 to 9.0% by weight, 2.0 to 9.0% by weight, 3.0 to 9.0% by weight, 4.0 to 9.0% by weight, 5 , 0 to 9.0 wt .-% or 5.0 to 8.0 wt .-%, and / or

c. in which the at least one copolymer is composed of two comonomers, and wherein the comonomer from group (a) of comonomers is acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from group (b) of comonomers is styrene or a styrene derivative, preferably Styrene is, and / or

d. further comprising at least one organic solvent, wherein the organic

Solvent preferably an aromatic solvent, more preferably one

is aromatic hydrocarbon, and is more preferably selected from toluene, xylene, trimethylbenzene, ethylbenzene, dimethylnaphthalene or a mixture thereof. In a further preferred embodiment of the process according to the invention, an amount of the additive which reduces the pour point by at least 1 ° C., preferably at least 2 ° C., at least 3 ° C., at least 4 ° C., at least 5, is added to the crude oil ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

In a further preferred embodiment of the method according to the invention, an amount of the additive is added to the crude oil such that the resulting

Crude oil composition 1 to 1000 ppmw, preferably 5 to 1000 ppmw or 5 to 750 ppmw, particularly preferably 5 to 500 ppmw, 10 to 500 ppmw, 10 to 300 ppmw or 15 to 250 ppmw of the at least one copolymer. In yet another aspect, the present invention relates to the use of a copolymer or mixture of copolymers composed of at least two comonomers, wherein all comonomers of the copolymer or copolymer mixture are selected from groups (a) and (b) of comonomers, and wherein the group (a) consists of comonomers of acrylic acid and methacrylic acid, and group (b) of

Comonomers of styrene or a styrene derivative, as an additive for improving the flow properties of paraffinic crude oil.

In particular, the invention according to this aspect relates to the use of the additive for lowering the pour point of paraffinic crude oil, preferably by at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

In a preferred embodiment, a copolymer or copolymer mixture is used which is dissolved in an organic solvent, wherein the copolymer or copolymer mixture 0.05 to 50 wt .-%, preferably 0.5 to 50 wt .-%, 1 to 50 wt. -%, 2.5 to 50 wt .-% or 5 to 50 wt .-%, more preferably 5 to 45 wt .-%, 10 to 45 wt .-%, 15 to 45 wt .-% or 15 to 40 Wt .-%, particularly preferably 20 to 40 wt .-% of the solution of copolymer or copolymer mixture and organic solvent. Preferably, the copolymer or copolymer mixture is in an aromatic

Solvent, preferably in a solvent of one or more aromatic Hydrocarbons, for example, from toluene, xylene, trimethylbenzene, ethylbenzene, dimethylnaphthalene or a mixture thereof.

The invention is described below purely by way of illustration with reference to FIG

Embodiments described in more detail.

Preparation of an additive for improving the flow properties of paraffinic crude oil. While stirring, a mixture of acrylic acid, styrene (or a styrene derivative) and hydrocarbon solvent was heated at a temperature of 95 ° C with N ₂ flow. The amount of the comonomer mixture in the formulation was 20.0 to 40.0% by weight.

The amount of acrylic acid was 0.6 to 10.0 wt .-%, based on the comonomer mixture. Thereafter, initiator (dibenzoyl peroxide) was used in an amount of 0.1 to 3.0 wt .-%, based on the comonomer mixture. The metering of the initiator was carried out at intervals of 40 minutes (4 to 6 times) (ratio of initiator to monomers: 0.1 to 3.0% by weight) to full conversion after about 160 to 240 minutes. Solubility of copolymers with different acrylic acid content.

It has been investigated how different acrylic acid moieties in the copolymer affect its solubility in hydrocarbons. It became a diesel fraction for the

Investigations used since the solubility / insolubility here can be easily observed with the naked eye. The result is shown in Tab.

Tab. 1: Influence of the amount of acrylic acid in the formulation on the solubility of the copolymer in hydrocarbons (diesel fraction). Amount of acrylic acid in the recipe

based on the comonomer mixture

[Wt .-%]

0.0 2.0 3.0 5.0 7.0 9.0

Soluble (Yes / No) Yes Yes Yes Yes Yes Yes

Copolymers made with 10% or more by weight of acrylic acid did not dissolve in hydrocarbons.

The effectiveness of the prepared copolymers as paraffin inhibitor (pour point depressants) was determined by measuring the pour point, determined according to ASTM D5853, to give the Saharan blend (Saharan Blend) grade with a pour point of +12.0 ° C (see Table 2).

Tab. 2: Influence of the amount of acrylic acid in the recipe on the pour point of "Sahara" crude oil.

Amount of acrylic acid, concentration pour point based on the comonomer mixture of the copolymer [° C]

(Dibenzoyl peroxide 2.0% by weight) [ppmw]

[Wt .-%]

0.0 150 + 10.0

2.0 150 +7.0

4.0 150 -2.0

5.0 150 -12.0

7.0 150 +1.0

10.0 150 + 12.0

The following are examples of preparing paraffin inhibitors

Copolymers of styrene / acrylic acid (S / AA) with different molecular weight (acrylic acid content in each case 5 wt .-%) described: example 1

1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene were added to a 500 ml beaker under a hood (protective gas stream). After gassing with inert gas (eg N ₂ or argon) for Vi hour at

Room temperature (25 ° C), the mixture was heated to a temperature of 95 ° C with constant stirring (300 rpm). Over a period of 320 minutes, a total of 0.075 g of dibenzoyl peroxide (dibenzoyl peroxide 0.25% by weight of the comonomer mixture) was added to the mixture at a constant temperature. The addition was carried out with a dosage of 5 x 0.015 g of dibenzoyl peroxide at intervals of about 40 minutes until the full conversion was reached. After the last addition of dibenzoyl peroxide, stirring was continued for 2 hours and 40 minutes. The resulting copolymer had a weight average molecular weight of 30,040 g / mol. Example 2

1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene were added to a 500 ml beaker under a hood (protective gas stream). After gassing with inert gas for one hour at room temperature (25 ° C), the mixture was heated to a temperature of 95 ° C with constant stirring (300 rpm). Over a period of 320 minutes, at a constant temperature, the mixture was admixed with a total of 0.15 g of dibenzoyl peroxide (dibenzoyl peroxide 0.50 wt

Comonomer mixture) was added. The addition was carried out with a dosage of 5 x 0.03 g of dibenzoyl peroxide at intervals of about 40 minutes until the full conversion was reached. After the last addition of dibenzoyl peroxide, stirring was continued for 2 hours and 40 minutes. The resulting copolymer had a weight average molecular weight of 21,750 g / mol.

Example 3

1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene were taken under a hood (protective gas stream) into a 500 ml beaker given. After gassing with inert gas for ¹ hour at room temperature (25 ° C), the mixture was heated to a temperature of 95 ° C with constant stirring (300 rpm). Over a period of 320 minutes, the mixture at a constant temperature of the mixture at a total of 0.30 g of dibenzoyl peroxide (dibenzoyl peroxide 1.00 wt .-% to the

Comonomer mixture) was added. The addition was carried out with a dosage of 5 x 0.06 g of dibenzoyl peroxide at intervals of about 40 minutes until the full conversion was reached. After the last addition of dibenzoyl peroxide, stirring was continued for 2 hours and 40 minutes. The resulting copolymer had a weight average molecular weight of 17,990 g / mol.

Examples 4, 5

Two further paraffin inhibitors were prepared according to the pattern described in Examples 1-3, the amount of dibenzoyl peroxide being 2.0 and 2.5% by weight, respectively. The copolymers produced had mass-average molecular weights of 11,580 g / mol and 10,510 g / mol, respectively.

The additives prepared in Examples 1-5 were added to "Sahara" crude oil and the pour point of the crude oil compositions of the invention thus prepared was determined (see Table 4).

Table 3: Influence of the molecular weight of the copolymer on the pour point of "Sahara" crude oil Example No. Amount of dibenzoyl peroxide M w concentration Concentration point based on the comonomer mixture [g / mol] of the copolymer [° C] (acrylic acid 5.0 wt .-%) [ppmw]

[Wt .-%]

Example 1 0.25 30.040 150 +12.0 Example 2 0.5 21.750 150 -20.0 Example 3 1.0 17.990 150 -21.0 Example 4 2.0 11.580 150 -12.0 Ex. 5 2.5 10.510 150 -10.0

The additive prepared in Example 3 was added to "Sibir" (pour point +17.0 ° C) and "Sahara" (pour point +12.0 ° C) crude at different concentrations, and the pour point of the resulting crude oil compositions was determined (see Tab. 4, 5).

Tab. 4: Cold properties of "Sibir" crude oil using 50 to 500 ppm

Copolymer S / AA

Example No. Concentration of the copolymer pour point

[ppmw] [° C]

Example 3 15 +15.0

Example 3 22.5 -4.0

Example 3 30 -21.0

Example 3 60 -21.0

Example 3 150 -21.0

Tab. 5: Cold properties of "Sahara" crude oil using 50 to 500 ppm of copolymer S / AA

Example No. Concentration of the copolymers pour point

[ppmw] [° C]

Example 3 15 + 12.0

Example 3 30 -10.0

Example 3 75 -20.0

Example 3 150 -21.0

Example 3 225 -21.0

Claims

A crude oil composition comprising a paraffinic crude oil and an amount of an additive which causes a lowering of the pour point of the crude oil, wherein the additive comprises at least one copolymer selected from at least two comonomers

wherein all comonomers composing the copolymer are selected from groups (a) and (b) of comonomers, and wherein group (a) consists of comonomers of acrylic acid and methacrylic acid, and group (b) of comonomers of styrene and a styrene derivative.

2. Crude oil composition according to claim 1, wherein the additive 0.05 to 50 wt .-%,

preferably 0.5 to 50 wt .-%, 1 to 50 wt .-%, 2.5 to 50 wt .-% or 5 to 50 wt .-%, more preferably 5 to 45 wt .-%, 10 to 45 Wt .-%, 15 to 45 wt .-% or 15 to 40 wt .-%, particularly preferably 20 to 40 wt .-% of the at least one copolymer comprises.

A crude oil composition according to claim 1 or 2, wherein the at least one copolymer has a weight average molecular weight of 2,000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to <30,000 g / mol, 10,000 to 30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol or 10,000 to 25,000 g / mol.

4. Crude oil composition according to one of the preceding claims, wherein the proportion of the comonomers of group (a) to the at least one copolymer, based on the comonomer mixture, 0.6 to <10.0 wt .-%, preferably 1.0 to <10 , 0 wt .-%, more preferably 1.0 to 9.0 wt .-%, 2.0 to 9.0 wt .-%, 3.0 to 9.0 wt .-%, 4.0 to 9 , 0% by weight, 5.0 to 9.0% by weight or 5.0 to 8.0% by weight.

Crude oil composition according to any one of the preceding claims, wherein the

at least one copolymer is composed of two comonomers, and wherein the comonomer from group (a) of comonomers is acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from group (b) of comonomers is styrene or a styrene derivative, preferably styrene.

A crude oil composition according to any one of the preceding claims, wherein the additive further comprises at least one organic solvent, and wherein the organic solvent is preferably an aromatic solvent, more preferably an aromatic hydrocarbon, and is more preferably selected from toluene, xylene, trimethylbenzene, ethylbenzene, Dimethylnaphthalene or a mixture thereof.

Crude oil composition according to any one of the preceding claims, comprising an amount of the additive which has a lowering of the pour point of the crude oil, determined according to ASTM D5853, of at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

Crude oil composition according to any one of the preceding claims, comprising 1 to 1000 ppmw, preferably 5 to 1000 ppmw or 5 to 750 ppmw, more preferably 5 to 500 ppmw, 10 to 500 ppmw, 10 to 300 ppmw or 15 to 250 ppmw of the at least one copolymer.

A process for preparing a crude oil composition having a pour point lowered from the crude oil, comprising adding an additive to the crude oil in an amount effective to lower the pour point, the additive comprising at least one copolymer composed of at least two comonomers, wherein all the comonomers composing the copolymer are selected from groups (a) and (b) of comonomers, and wherein group (a) consists of comonomers of acrylic acid and methacrylic acid, and group (b) of comonomers consists of styrene and a styrene derivative ,

10. The method of claim 9, wherein an additive is added to the crude oil, the 0.05 to 50 wt .-%, preferably 0.5 to 50 wt .-%, 1 to 50 wt .-%, 2.5 to 50 Wt% or 5 to 50 wt%, more preferably 5 to 45 wt%, 10 to 45 wt%, 15 to 45 wt% or 15 to 40% by weight, particularly preferably 20 to 40% by weight of the at least one copolymer.

11. The method of claim 9 or 10, wherein an additive is added to the crude, a. wherein the at least one copolymer has a weight average molecular weight of 2,000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to <30,000 g / mol, 10,000 to 30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol or 10,000 to 25,000 g / mol, and / or

b. in which the proportion of the comonomers of group (a) on the at least one

Copolymer, based on the comonomer mixture, 0.6 to <10.0 wt .-%, preferably 1.0 to <10.0 wt .-%, more preferably 1.0 to 9.0 wt .-%, 2, 0 to 9.0 wt%, 3.0 to 9.0 wt%, 4.0 to 9.0 wt%, 5.0 to 9.0 wt% or 5.0 to 8.0 wt .-%, and / or

c. in which the at least one copolymer is composed of two comonomers, and wherein the comonomer from group (a) of comonomers is acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from group (b) of comonomers is styrene or a styrene derivative, preferably Styrene is, and / or d. which further comprises at least one organic solvent, wherein the organic solvent is preferably an aromatic solvent, more preferably an aromatic hydrocarbon, and is more preferably selected from toluene, xylene, trimethylbenzene, ethylbenzene, dimethylnaphthalene or a

Mixture of it.

12. The method according to any one of claims 9 to 11, wherein the crude oil is an amount of

Additive is added, which is a lowering of the pour point, determined according to ASTM D5853, by at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C causes.

A process according to any one of claims 9 to 12, wherein an amount of the additive is added to the crude such that the crude oil composition is from 1 to 1000 ppmw, preferably 5 to 1000 ppmw or 5 to 750 ppmw, more preferably 5 to 500 ppmw, 10 to 500 ppmw, 10 to 300 ppmw or 15 to 250 ppmw of the at least one

Contains copolymer.

14. Use of a copolymer or mixture of copolymers composed of at least two comonomers, wherein all comonomers of the copolymer or

Copolymer mixtures are selected from the groups (a) and (b) of comonomers, and wherein the group (a) consists of comonomers of acrylic acid and methacrylic acid, and the group (b) of comonomers of styrene or a styrene derivative, as an additive for improvement the flow properties of paraffinic crude oil.

15. Use according to claim 14, for lowering the pour point of paraffinic crude oil, preferably at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

16. Use according to claim 14 or 15, wherein the copolymer or copolymer mixture is dissolved in an organic solvent, and wherein the copolymer or copolymer mixture 0.05 to 50 wt .-%, preferably 0.5 to 50 wt .-%, 1 to 50 wt .-%, 2.5 to 50 wt .-% or 5 to 50 wt .-%, more preferably 5 to 45 wt .-%, 10 to 45 wt .-%, 15 to 45 wt .-% or 15 to 40 wt .-%, particularly preferably 20 to 40% by weight of the solution of copolymer or copolymer mixture and organic solvent.

17. Use according to claim 16, wherein the copolymer or copolymer mixture is present in an aromatic solvent, preferably in an aromatic solvent which is selected from toluene, xylene, trimethylbenzene, ethylbenzene, dimethylnaphthalene or a mixture thereof.